Amateur radio has a long and proud tradition of public service in the
United States and around the world. One example is to provide emergency
communications in natural disasters such as hurricanes or floods. The Amateur
Radio Emergency Service (ARES) is a part of the American
Radio Relay League, the national organization of U.S. Amateur Radio
Operators, that provides centralized management structure for these emergency
services. But, the real heart and soul of amateur radio public service are
the ham operators who donate their time, equipment,
skills and data.

One aspect of amateur radio public service is supplying atmospheric data
to various users, including individuals and federal, state and local governments.
Many amateur radio operators operate their own weather stations to collect
local weather data and transmit these data for anyone to receive and use.
Oftentimes, receivers capable of receiving and displaying this weather
information are located at local National Weather Service Offices where
forecasters can monitor the data.

The Automatic
Position Reporting System (APRS tm) is a part of ham radio that
provides an ideal way for weather station operators to distribute their
weather data much further than the regions within their transmitter range.
APRS was originally intended for position information data but actually
provides a means for automatic transmission of all sorts of digital data.
This is especially true now that the original APRS packet radio concept has
been enhanced to include the capabilities of the Internet. The reporting of
citizen weather data is a particularly useful application of the APRS
Internet Service (APRS-IS).

The Citizen Weather Observer Program
(CWOP) is a group of ham radio operators and other private citizens around
the country that have volunteered the use of their weather data for
education, research and use by interested parties. The APRS-IS collects
weather data transmitted from individual stations and communicates these data
to the amateur radio findU server where the data are organized and made
available to the MADIS
Program at 15-minute intervals. The CWOP data also go to the MADIS Quality Control and
Monitoring System (QCMS) which checks data quality using a variety of
techniques. Based on these checks, data may be declared questionable.
Occasional questionable data is normal. However, a high percentage of
questionable data may indicate instrument or siting problems.

The results of this quality checking are then made available to the
station operators on the CWOP
Data Quality web page. This feedback to the weather station owners
can alert them when a problem has developed. The goal here is to provide
tools for station owners to help them keep the data quality high so that the
data can be widely used with confidence.